Long story short, I was trying out new kernels, got stuck in a boot loop, nothing would fix it, so I tried to restore back to stock rom. I did it manually in fastboot mode, but the bootloader .img would not write. It gave an error saying mismatched signatures. I redownloaded the image, I tried using a couple of different methods, like using toolkits and various commands, and finally, without thinking, erased the bootloader using the fastboot erase command with the intent of re-writing it, which obviously I can not do or I would no longer be here. It still boots, in the sense that I hear the notification on the computer that a device has been connected, but it shows up as NVidia APX in my list of devices on windows instead of Nexus 7 now, and the screen shows nothing. So... how screwed am I? If it is hopeless, is there any way to return/replace it (without using questionable methods)? Thanks.